Click right to "Go to source code" with Texstudio

I also had this bug recently. The bug is not related with the actual application; it is due to corrupted profile. This is what I learned after some experimentation. So, for the Mac OS, look at your home directory--> there is a hidden Config folder there. There is Texstudio folder inside the config folder. Close Textstudio and remove the Texstudio.ini (the profile file) file in the folder. Texstudio will recreate the file when you restart it. This fixes the problem.

New answer inspired by @Dellu: you need to restore the default settings to fix this problem. Just delete the settings file (texstudio.ini), while Texstudio is not running. Otherwise it will recreate the file with the present settings on closing. Note: If you only want to restore the default settings temporarily, rename texstudio.ini (e.g. texstudio-backup.ini).

Update that might be helpful for other users: I upgraded to TeXstudio 2.12.16. Then, while I was in the editor I used the "go to PDF" command, nothing happened. Moreover, I right-clicked on the PDF, there was no option "go to source". I solved this issue again by deleting the default settings (texstudio.ini, which is on C:\Users...\AppData\Roaming\texstudio in Windows 7), while Texstudio is not running.

Old answer: Let me post a simple trick: left click in the pdf viewer goes one page down, then right click goes one page up and the "go to source code" opens!